The invention is based on an apparatus having an optical sensor for detecting operating data of an internal combustion engine. The optical sensor generates an output signal via an amplifier to an evaluation circuit which interprets engine parameters. German Patent Application No. P 29 05 506.9 discloses an ignition onset sensor for internal combustion engines. It comprises an opto-electrical converter which communicates with the combustion chamber and whose signals may be used, for instance, for regulating the onset of ignition.
Processing optical signals derived from occurrences in the combustion chamber of an internal combustion engine is increasingly significant, because only in this manner is it possible to intervene directly into the operating behavior of an internal combustion engine. This is particularly important in seeking to attain the cleanest possible exhaust gas, smooth engine operation and economical fuel consumption.
The processing of opto-electrical signals is internal combustion engines has proved to be extremely problematical, because the signal transducers are relatively prone to soiling, and the danger thus exists that the measurement results will be adulterated. Problems also arise with the varying light yield when the engine load status varies.